Lumbar Vertebrae - Anatomy Pictures and Information Home > Skeletal System > Spine > Lumbar Vertebrae Lumbar Vertebrae The lumbar vertebrae consist of five individual cylindrical bones that form the spine in the lower back. These vertebrae carry all of the upper body’s weight while providing flexibility and movement to the trunk region. They also protect the delicate spinal cord and nerves within their vertebral canal. Found along the body’s midline in the lumbar (lower back) region, the lumbar vertebrae make up the region of the spine inferior to the thoracic vertebrae in the thorax and superior to the sacrum and coccyx in the pelvis.... Move up/down/left/right: Click compass arrows Rotate image: Click and drag in any direction, anywhere in the frame Identify objects: Click on them in the image 2D Interactive 3D Rotate & Zoom Change Anatomical System Vertebra and Spinal Cord, Cross-section Full Lumbar Vertebrae Description [Continued from above] . . . The lumbar vertebrae are stacked to form a continuous column in order from superior (L1 or first lumbar vertebra) to inferior (L5 or fifth lumbar vertebra).

Together they create the concave lumbar curvature in the lower back. Connecting each vertebra to its neighboring vertebra is an intervertebral disk made of tough fibrocartilage with a jelly-like center. The outer layer of the intervertebral disk, the annulus fibrosus, holds the vertebrae together and provides strength and flexibility to the back during movement. The jelly-like nucleus pulposus acts as a shock absorber to resist the strain and pressure exerted on the lower back. The lumbar vertebrae are the some of the largest and heaviest vertebrae in the spine, second in size only to the sacrum. A cylinder of bone known as the vertebral body makes up the majority of the lumbar vertebrae’s mass and bears most of the body’s weight. Posteriorly the body is connected to a thin ring of bone known as the arch. The arch surrounds the hollow vertebral foramen and connects the body to the bony processes on the posterior of the vertebra. The vertebral foramen is a large, triangular opening in the center of the vertebra that provides space for the spinal cord, cauda equina, and meninges as they pass through the lower back.

Extending from the vertebral arch are several bony processes that are involved in muscle attachment and movement of the lower back. The spinous process extends from the posterior end of the arch as a thin rectangle of bone. It serves as a connection point for the muscles of the back and pelvis, such as the psoas major and interspinales. On the left and right lateral sides of each vertebra are the short, triangular transverse processes. The transverse processes form important connection points for many muscles, including the rotatores and multifidus muscles that extend and rotate the trunk. Unlike the cervical vertebrae in the neck, the lumbar vertebrae lack the transverse foramina in the transverse processes, and also lack facets to either side of the body. The fifth lumbar vertebra is distinct from the L1-4 vertebrae in being much larger on its front side than in the back. Its spinous process, on the other hand, is smaller than in the other lumbar vertebrae with a wide, four-sided shape that comes to a rough edge and a thick notch.

Prepared by Tim Taylor, Anatomy and Physiology Instructor Human Spine & Spinal Cord Picture C1 - S5 Vertebra Can learn to drive an adapted vehicle. Most likely will need to use a manual wheelchair. Should be able to cough productively (if abdominal muscles are intact). A fair to good ability to control and balance the body while in a seated position. Some patients will be capable of standing in a standing frame, while others may require the use of braces to walk. Often will have little or no voluntary control of bowel or bladder function but can usually manage on their own with adaptive equipment. T1 - Comparatively speaking, T1 is the smallest of all thoracic vertebrae. The T1 vertebra is the first (uppermost) of the twelve (12) thoracic vertebrae that make up the central and largest section of the spinal column between the lumbar vertebrae below and the cervical vertebrae above. T2 - The second vertebra in the thoracic spine is responsible for helping to support the rib cage.

The T2 vertebra possesses facets that create joints with two of the ribs, thus helping to keep the thoracic spine far more stable than the cervical spine in the neck or the lumbar spine in the lower back. T2 vertebra degeneration include: Herniated, bulging or prolapsed discs, Bone spurs, Facet disease, Forms of osteoarthritis and Traumatic or sports-related injuries. T3 - The third thoracic vertebrae is a small vertebra in the upper middle back that plays an integral role in supporting the rib cage. The anterior aspect of the upper thoracic spine is a difficult region to approach in spinal surgery. T4 - Spinal cord transection at T4 results in severe damage of the nervous tissue, with impairment of motor, sensory and autonomic functions. T4 syndrome is a relatively uncommon condition in which spinal injury at the T4 vertebra causes a set of symptoms including diffuse arm pain and pins and needles or numbness in the upper arm. T5 - The T5 vertebra, as well as the rest of the thoracic spine, provides a stable foundation for the human rib cage.

T6 - An injury at the level of T6 (thoracic) spinal cord results in damage to the autonomic nervous system, both the sympathetic and parasympathetic divisions, affecting the function of major abdominal organs. T7 - The T7 vertebra is in the middle of the twelve (12) thoracic vertebrae of the torso and the center of the spinal column. Thoracic vertebrae play an important role, not only in the protection of the spinal cord, but also in the protection of vital organs. A vertebral compression fracture refers to a break of the vertebral body, most often below the T7 level of the thoracic spine (upper back), and is most commonly caused by weakened bone resulting from osteoporosis. Most vertebral compression fractures result in a loss of more than 15% to 20% of the height of the vertebra. T8 - T8 vertebra is toward the lower (caudal) end of the twelve (12) thoracic vertebrae within the central, torso section of the spine. Like other spinal vertebrae, the T8 primarily protects and encases the spinal cord.

The T8 is also at the same level as the xiphoid process. The eighth thoracic spinal nerve runs beneath the T8. Throughout the thoracic spine, discs like those above and beneath the T8 vertebra can become damaged and cause painful symptoms. T9 - T9 to T12 are known as the transition vertebrae. The lumbar cord is situated between T9 and T11 vertebrae. T9 to T12 injuries can be classified as either complete or incomplete injuries. Complete injuries result in the total loss of movement and sensation below the point of injury, while incomplete injuries indicate that some function below the level of injury is retained. T10 - T10 is situated at the umbilicus. The T10 vertebra is near to the bottom of the twelve (12) thoracic vertebrae (T1-T12) within the torso and making up the central portion of the spinal column. This particular vertebra has a complete articular facet and the thoracic spinal nerves passes out under it. T10 innervates the muscles of the lower abdomen. It is part of the section of the spinal cord which is most vulnerable to injury due to the area's high level of flexibility.

An injury in this area will most likely experience limited or complete loss of use of the muscles in the lower abdomen, buttocks, legs, and feet. Extent of disability is determined by damage done to the T10 vertebra. Partial damage may cause weakness, numbness, lack of muscle control, or loss of the use of one side of the lower body. Complete damage could result in the loss of use of the lower body (paraplegia). T11 - The ribs connected to T11 and T12 at the bottom of the thoracic spine do not attach the sternum in front, but do provide protection for the kidneys in the back of the body. Because these levels have slightly less stability, they are slightly more prone to problems that can cause pain. A person with a T11 vertebral injury may have or recover sensations in the L1 through L4 dermatomes which include the front of the leg down to the mid-shin level. In addition, such a patient should recover hip extensors, knee extensors, and even ankle dorsiflexion. However, the sacral functions, including bowel and bladder and many of the flexor functions of the leg may be absent or weak.

T12 - T12 ends just above the hip girdle. T12 bears the most weight of any thoracic vertebra, making it the strongest thoracic vertebra, but also the most susceptible to stress-related injuries. Compression fractures of the spine usually occur at the bottom part of the thoracic spine (T11 and T12) and the first vertebra of the lumbar spine (L1). The most common thoracic spinal cord injury involves T11 and T12. Lumbar Vertebrae (L1 to L5) Lumbar nerves (L1 to L5) injuries generally result in some loss of function in the hips and legs. Often there is little or no voluntary control of bowel or bladder, but patients usually manage on their own with the use of special equipment. Depending on strength in the legs, some patients may need a wheelchair and may also walk with braces. The lumbar vertebrae graduate in size from L1 through L5. These vertebrae bear much of the body's weight and related biomechanical stress.

The lumbar vertebrae are also the largest segments of the movable part of the vertebral column, and are characterized by the absence of the foramen transversarium within the transverse process, and by the absence of facets on the sides of the body. Some individuals have four lumbar vertebrae, while others have six. Lumbar disorders that normally affect L5 will affect L4 or L6 in these individuals. L1 - The first lumbar vertebra is at the same level as the ninth rib. This level is also called the important transpyloric plane, since the pylorus of the stomach is at this level. L2 - Injuries to the spinal column at L2 or lower will damage the tip of the spinal cord, called the conus, or the spray of spinal roots that are descending to the appropriate spinal vertebral levels to exit the spinal canal or the caudal equina. L3 - The L3 vertebra is in the middle of the five lumbar vertebrae in the lower back portion of the spinal column.

The L3 vertebra, or third lumbar vertebra, is one of the most common sites for the occurrence of a herniated disc and other spinal conditions that can cause chronic lower back pain. A lot of motion in the back is divided between these five motion segments with segments L3 - L4 and L4 - L5 taking most of the stress. L3 - L4 and L4 - L5 segments are most likely to breakdown from wear and tear causing such conditions as osteoarthritis. L2 and L3 cover the front part of the thighs. L4 - The most likely to herniate ( herniated disc , bulging disk , compressed disk, herniated intervertebral disk, herniated nucleus pulposus, prolapsed disk, ruptured disk, slipped disk). The effects of this can cause pain and numbness that can radiate through the leg and extend down to the feet (sciatica). Spondylolysis and spondylolisthesis are conditions that affect the moveable joints of the spine that help keep the vertebrae aligned one on top of the other. Spondylolysis is actually a weakness or stress fracture in one of the bony bridges that connects the upper and lower facet joints.

This fracture can happen at any level of the spine but usually occurs at the fourth (L4) or fifth (L5) lumbar vertebra. L4 and L5 fractures are commonly the result of a high impact trauma from falls or motor vehicle accidents. L5 - The fifth lumbar vertebra (L5) is the largest of the five lumbar vertebrae and is considered an atypical vertebra due to its shape. As the last of the lumbar vertebrae, the L5 vertebra bears more body weight than any of the other 23 vertebrae that sit atop it in the vertebral column. The L4 and L5 disc, in between the L4 and L5 vertebrae, can herniate or degenerate, leading to possible leg pain (sciatica) and/or lower back pain. The fifth lumbar vertebra is the most common site of spondylolysis and spondylolisthesis. Sacral Nerves (S1 to S5) injuries generally result in some loss of functionin the hips and legs. Little or no voluntary control of bowel or bladder, but patients can manage on their own with special equipment Most likely they will also still be able to walk.

Sacral Nerves (S1 to S5) The sacrum is shaped different in males and females. In females the sacrum is shorter and wider than in males. The Sacrum is located behind the pelvis. Five bones (abbreviated S1 through S5) fused into a triangular shape, form the sacrum. The sacrum fits between the two hipbones connecting the spine to the pelvis located just below the lumbar vertebrae. The Sacrum consists of four or five sacral vertebrae in a child, which become fused into a single bone after age 26. The sacrum forms the back wall of the pelvic girdle and moves with it. The first three vertebrae in the sacral have transverse processes which come together to form wide lateral wings called alae. These alae articulate with the blades of the pelvis (ilium). As part of the pelvic girdle, the sacrum forms the back wall of the pelvis and also forms joints at the hip bone called the sacroiliac joints. The sacrum contains a series of four openings on each side through which the sacral nerves and blood vessels run.

The sacral canal runs down the center of the sacrum and represents the end of the vertebral canal. Back pain or leg pain ( sciatica ) can typically arise due to injury where the lumbar spine and sacral region connect (at L5 - S1) because this section of the spine is subjected to a large amount of stress and twisting. People with rheumatoid arthritis or osteoporosis are inclined to develop stress fractures and fatigue fractures in the sacrum. The bottom of the spinal column is called the coccyx or tailbone. It consists of 3 to 5 bones that are fused together in an adult. Many muscles connect to the coccyx. Sacral Nerves (S1 to S5) injuries generally result in some loss of function in the hips and legs. Little or no voluntary control of bowel or bladder, but can manage on their own with special equipment Most likely will be able to walk. S1 - L5 to S1 Isthmic Spondylolisthesis: A small fracture in the facet joints can allow the L5 vertebra to slip forward over the S1 vertebra, impinging the nerve root and leading to leg pain and other symptoms.

L5-S1 disc herniation: Occurs when the inner portion leaks out and touches the nearby nerve root, causing pain to radiate in the lower back and/or down the leg. L5-S1 degenerative disc disease: If the L5-S1 disc is compromised, the L5-S1 disc itself can become a source of lower back and/or leg pain. S2 - S2 is located at the level of posterior superior iliac spine. S2 covers the back of the thighs. S3 - S3 cover the medial side of the buttocks. S4 - S4-5 covers the perineal region. S5 - S5 is the lowest dermatome and represents the skin immediately at and adjacent to the anus. This chart is a guide, with general information only; impairments and rehabilitation potential can vary depending on the type and severity of SCI .

BBC Science & Nature - Human Body and Mind - Skeleton Layer S-shaped spine: Prevents shock to your head when you walk or run Spinal cord protection: Your bony spine encases your delicate spinal cord Vertebrae: 33 vertebrae make up your spine Column of ring-like bones Also known as your backbone, your spine is a strong, flexible column of ring-like bones that runs from your skull to your pelvis. It holds your head and body upright and allows you to bend and twist your body. It also offers protection to your spinal cord - a large bundle of nerves that runs through the cavity in the centre of your spine that relays messages between your brain and the rest of your body. Vertebrae Your spine is made up of 33 irregularly shaped bones called vertebrae. Each vertebra has a hole in the middle through which the spinal cord runs.

The spinal cord can be divided into five different regions, from top to bottom: Your 7 cervical vertebrae support your head and neck and allow you to nod and shake your head Your ribs attach to your 12 thoracic vertebrae Your five sturdy lumbar vertebrae carry most of the weight of your upper body and provide a stable centre of gravity when you move Your sacrum is made up of five fused vertebrae. It makes up the back wall of your pelvis Your coccyx is made up of four fused vertebrae. It is an evolutionary remnant of the tail found in most other vertebrates Shock absorbers Sandwiched between your vertebrae are pads of tough, fibrous cartilage called intervertebral discs that cushion your vertebrae and absorb shock. These discs, together with the curved, S-shape of your spine, prevent shock to your head when you walk or run. Flexibility The joints between individual vertebrae aren't very flexible. But working together they give the spine a wide range of movement, allowing you to arch backwards, bend forwards and twist from side to side. During strenuous movement, strong ligaments and muscles around your vertebrae stabilise your spine and help to control movement.

Spine Anatomy, Anatomy of the Human Spine Anatomy of the Human Spine Overview The spine is made of 33 individual bones stacked one on top of the other. This spinal column provides the main support for your body, allowing you to stand upright, bend, and twist, while protecting the spinal cord from injury. Strong muscles and bones, flexible tendons and ligaments, and sensitive nerves contribute to a healthy spine. Yet, any of these structures affected by strain, injury, or disease can cause pain. Spinal curves When viewed from the side, an adult spine has a natural S-shaped curve. The neck (cervical) and low back (lumbar) regions have a slight concave curve, and the thoracic and sacral regions have a gentle convex curve (Fig. 1). The curves work like a coiled spring to absorb shock, maintain balance, and allow range of motion throughout the spinal column. Figure 1. The spine has three natural curves that form an S-shape; strong muscles keep our spine in alignment. Figure 2. The five regions of the spinal column. The muscles and correct posture maintain the natural spinal curves.

Good posture involves training your body to stand, walk, sit, and lie so that the least amount of strain is placed on the spine during movement or weight-bearing activities (see Posture ). Excess body weight, weak muscles, and other forces can pull at the spine's alignment: An abnormal curve of the lumbar spine is lordosis, also called sway back. An abnormal curve of the thoracic spine is kyphosis, also called hunchback. An abnormal curve from side-to-side is called scoliosis. Muscles The two main muscle groups that affect the spine are extensors and flexors. The extensor muscles enable us to stand up and lift objects. The extensors are attached to the back of the spine. The flexor muscles are in the front and include the abdominal muscles. These muscles enable us to flex, or bend forward, and are important in lifting and controlling the arch in the lower back. The back muscles stabilize your spine. Something as common as poor muscle tone or a large belly can pull your entire body out of alignment. Misalignment puts incredible strain on the spine (see Exercise for a Healthy Back ). Vertebrae Vertebrae are the 33 individual bones that interlock with each other to form the spinal column.

The vertebrae are numbered and divided into regions: cervical, thoracic, lumbar, sacrum, and coccyx (Fig. 2). Only the top 24 bones are moveable; the vertebrae of the sacrum and coccyx are fused. The vertebrae in each region have unique features that help them perform their main functions. Cervical (neck) - the main function of the cervical spine is to support the weight of the head (about 10 pounds). The seven cervical vertebrae are numbered C1 to C7. The neck has the greatest range of motion because of two specialized vertebrae that connect to the skull. The first vertebra (C1) is the ring-shaped atlas that connects directly to the skull. This joint allows for the nodding or “yes” motion of the head. The second vertebra (C2) is the peg-shaped axis, which has a projection called the odontoid, that the atlas pivots around. This joint allows for the side-to-side or “no” motion of the head. Thoracic (mid back) - the main function of the thoracic spine is to hold the rib cage and protect the heart and lungs.

The twelve thoracic vertebrae are numbered T1 to T12. The range of motion in the thoracic spine is limited. Lumbar (low back) - the main function of the lumbar spine is to bear the weight of the body. The five lumbar vertebrae are numbered L1 to L5. These vertebrae are much larger in size to absorb the stress of lifting and carrying heavy objects. Sacrum - the main function of the sacrum is to connect the spine to the hip bones (iliac). There are five sacral vertebrae, which are fused together. Together with the iliac bones, they form a ring called the pelvic girdle. Coccyx region - the four fused bones of the coccyx or tailbone provide attachment for ligaments and muscles of the pelvic floor. While vertebrae have unique regional features, every vertebra has three functional parts (Fig. 3): Figure 3. While vertebrae have unique regional features, every vertebra has three main parts: body (purple), vertebral arch (green), and processes for muscle attachment (tan).

a drum-shaped body designed to bear weight and withstand compression (purple) an arch-shaped bone that protects the spinal cord (green) star-shaped processes designed as outriggers for muscle attachment (tan) Intervertebral discs Each vertebra in your spine is separated and cushioned by an intervertebral disc, keeping the bones from rubbing together. Discs are designed like a radial car tire. The outer ring, called the annulus, has criss-crossing fibrous bands, much like a tire tread. These bands attach between the bodies of each vertebra. Inside the disc is a gel-filled center called the nucleus, much like a tire tube (Fig. 4). Figure 4. Intervertebral discs (purple) are made of a gel-filled center called the nucleus and a tough fibrous outer ring called the annulus. The annulus pulls the vertebral bodies together against the resistance of the gel-filled nucleus. Discs function like coiled springs. The criss-crossing fibers of the annulus pull the vertebral bodies together against the elastic resistance of the gel-filled nucleus. The nucleus acts like a ball-bearing when you move, allowing the vertebral bodies to roll over the incompressible gel.

The gel-filled nucleus is composed mostly of fluid. This fluid absorbed during the night as you lie down and is pushed out during the day as you move upright. With age, our discs increasingly lose the ability to reabsorb fluid and become brittle and flatter; this is why we get shorter as we grow older. Also diseases, such as osteoarthritis and osteoporosis, cause bone spurs (osteophytes) to grow. Injury and strain can cause discs to bulge or herniate, a condition in which the nucleus is pushed out through the annulus to compress the nerve roots causing back pain. Vertebral arch & spinal canal On the back of each vertebra are bony projections that form the vertebral arch. The arch is made of two supporting pedicles and two laminae (Fig. 5). The hollow spinal canal contains the spinal cord, fat, ligaments, and blood vessels. Under each pedicle, a pair of spinal nerves exits the spinal cord and pass through the intervertebral foramen to branch out to your body. Figure 5. The vertebral arch (green) forms the spinal canal (blue) through which the spinal cord runs.

Seven bony processes arise from the vertebral arch to form the facet joints and processes for muscle attachment. Surgeons often remove the lamina of the vertebral arch (laminectomy) to access and decompress the spinal cord and nerves to treat spinal stenosis, tumors, or herniated discs. Seven processes arise from the vertebral arch: the spinous process, two transverse processes, two superior facets, and two inferior facets. Facet joints The facet joints of the spine allow back motion. Each vertebra has four facet joints, one pair that connects to the vertebra above (superior facets) and one pair that connects to the vertebra below (inferior facets) (Fig. 6). Figure 6. The superior and inferior facets connect each vertebra together. There are four facet joints associated with each vertebra. Ligaments The ligaments are strong fibrous bands that hold the vertebrae together, stabilize the spine, and protect the discs. The three major ligaments of the spine are the ligamentum flavum, anterior longitudinal ligament (ALL), and posterior longitudinal ligament (PLL) (Fig. 7).

The ALL and PLL are continuous bands that run from the top to the bottom of the spinal column along the vertebral bodies. They prevent excessive movement of the vertebral bones. The ligamentum flavum attaches between the lamina of each vertebra. Figure 7. The ligamentum flavum, anterior longitudinal ligament (ALL), and posterior longitudinal ligament (PLL) allow the flexion and extension of the spine while keeping the vertebrae in alignment. Spinal cord The spinal cord is about 18 inches long and is the thickness of your thumb. It runs within the protective spinal canal from the brainstem to the 1st lumbar vertebra. At the end of the spinal cord, the cord fibers separate into the cauda equina and continue down through the spinal canal to your tailbone before branching off to your legs and feet. The spinal cord serves as an information super-highway, relaying messages between the brain and the body. The brain sends motor messages to the limbs and body through the spinal cord allowing for movement. The limbs and body send sensory messages to the brain through the spinal cord about what we feel and touch. Sometimes the spinal cord can react without sending information to the brain.

These special pathways, called spinal reflexes, are designed to immediately protect our body from harm. The nerve cells that make up your spinal cord itself are called upper motor neurons. The nerves that branch off your spinal cord down your back and neck are called lower motor neurons. These nerves exit between each of your vertebrae and go to all parts of your body. Any damage to the spinal cord can result in a loss of sensory and motor function below the level of injury. For example, an injury to the thoracic or lumbar area may cause motor and sensory loss of the legs and trunk (called paraplegia). An injury to the cervical (neck) area may cause sensory and motor loss of the arms and legs (called tetraplegia, formerly known as quadriplegia). Spinal nerves Thirty-one pairs of spinal nerves branch off the spinal cord. The spinal nerves act as telephone lines, carrying messages back and forth between your body and spinal cord to control sensation and movement. Each spinal nerve has two roots (Fig. 8). The ventral (front) root carries motor impulses from the brain and the dorsal (back) root carries sensory impulses to the brain.

The ventral and dorsal roots fuse together to form a spinal nerve, which travels down the spinal canal, alongside the cord, until it reaches its exit hole - the intervertebral foramen (Fig. 9). Once the nerve passes through the intervertebral foramen, it branches; each branch has both motor and sensory fibers. The smaller branch (called the posterior primary ramus) turns posteriorly to supply the skin and muscles of the back of the body. The larger branch (called the anterior primary ramus) turns anteriorly to supply the skin and muscles of the front of the body and forms most of the major nerves. Figure 8. The ventral (motor) and dorsal (sensory) roots join to form the spinal nerve. The spinal cord is covered by three layers of meninges: pia, arachnoid and dura mater. The spinal nerves are numbered according to the vertebrae above which it exits the spinal canal. The 8 cervical spinal nerves are C1 through C8, the 12 thoracic spinal nerves are T1 through T12, the 5 lumbar spinal nerves are L1 through L5, and the 5 sacral spinal nerves are S1 through S5.

There is 1 coccygeal nerve. Figure 9. The spinal nerves exit the spinal canal through the intervertebral foramen below each pedicle. The spinal nerves innervate specific areas and form a striped pattern across the body called dermatomes (Fig. 10). Doctors use this pattern to diagnose the location of a spinal problem based on the area of pain or muscle weakness. For example leg pain ( sciatica ) usually indicates a problem near the L4-S3 nerves. Figure 10. A dermatome pattern shows which spinal nerves are responsible for sensory and motor control of specific areas of the body. Coverings & spaces The spinal cord is covered with the same three membranes as the brain, called meninges. The inner membrane is the pia mater, which is intimately attached to the cord. The next membrane is the arachnoid mater. The outer membrane is the tough dura mater (Fig. 8). Between these membranes are spaces used in diagnostic and treatment procedures. The space between the pia and arachnoid mater is the wide subarachnoid space, which surrounds the spinal cord and contains cerebrospinal fluid (CSF).

This space is most often accessed when performing a lumbar puncture to sample and test CSF or during a myelogram to inject contrast dye. The space between the dura mater and the bone is the epidural space. This space is most often accessed to deliver anesthetic numbing agents, commonly called an epidural, and to inject steroid medication (see Epidural Steroid Injections ). Sources & links Lumbar Vertebrae Lumbar vertebrae Compressed Vertebrae The lumbar vertebrae are located in the lower back and support most of the upper body’s weight. Although most people have five, about 10 percent of adults have some sort of anatomical abnormality within the lower back, the most common of which is a sixth lumbar vertebra. The presence of an additional lumbar vertebra does not lead to a greater chance of lower back pain or the development of a spine condition. No matter how many lumbar vertebrae a person has, the lower back’s relative flexibility and weight-bearing function make it the region of the back that is most vulnerable to spinal conditions that can cause chronic and debilitating pain.

These conditions can occur at any point along the lumbar vertebrae and can travel into the buttocks, legs and feet if severe. About the lumbar vertebrae The lumbar vertebrae are segmented as follows: L1 — The top of the lumbar region; here, the spinal cord ends and the cauda equina branches downward through the sacrum to the coccyx. L3 — The high range of motion here leads to breakdown from wear and tear associated with degenerative disc disease and osteoarthritis; the sciatic nerve originates here. L5 — The vertebral body is deeper in front than most other vertebrae; there is a smaller spinous process, and thicker transverse processes; this is the most common site of herniated discs and spondylolisthesis. L6 — Rarely found in most people, but vulnerable to the same sort of spine conditions experienced at the L5 level in others. Treating lumbar spine conditions Typically, chronic lower back pain symptoms can be managed through a course of conservative treatment recommended by your physician. This usually includes a combination of physical therapy and pain medication, as well as other pain management strategies.

If pain continues within the lumbar vertebrae even after months of conservative treatment, you may be a candidate for minimally invasive spine surgery at Laser Spine Institute. Our minimally invasive procedures offer patients a safer and effective treatment alternative to traditional open back surgery. To treat many lumbar spine conditions, we provide minimally invasive decompression and minimally invasive stabilization surgery. Both procedures aim to relieve pressure on the pinched nerve while maintaining stabilization in the spine, either naturally or with the help of an artificial disc or bone graft. Though our decompression surgery is the most common of our procedure performed, some patients with severe cases do require a stabilization surgery. Find out if you are a candidate for our minimally invasive spine surgery by contacting Laser Spine Institute today and asking for a review of your MRI report or CT scan. Want to chat? Spine Anatomy Video Collectively, the vertebral bodies comprise the boney building blocks of the spine. They are stacked on top of each other with a disc in between each one. All of the vertebral bodies act as a support column to hold up the spine. This column supports about half of the weight of the body, with the other half supported by the muscles.

Each area of the spine has some differences in the form and function of vertebral bodies and how they are attached to adjacent structures. Vertebral Bodies in the Cervical Spine (Neck) Cervical Spine Anatomy Video The cervical spine has seven vertebral bodies (segments). The top two segments are unique: The first cervical segment (called the atlas) is a ring that does not have a vertebral body. It is attached to the second vertebral body (the axis), which acts as a post that the first vertebral ring rotates around. Most of the rotation in the neck is located in these top two segments. Like the rest of the spine, the next five vertebral segments have three joints at each segment, including one disc in the front and paired facet joints in the back. Unlike the rest of the spine, the segments in the cervical spine contain openings in each vertebral body for arteries to carry blood to the brain (vertebral artery running through the transverse foramen). Lumbar Spine Anatomy Video The thoracic spine has twelve vertebral bodies. These structures have very little motion because they are firmly attached to the ribs and sternum (breastbone).

Because there is little motion, this region of the spine is not usually a source of back pain, although the junction between the spine and the ribs (costovertebral junction) can be a source of pain. Vertebral Bodies in the Lumbar Spine (Lower Back) The lumbar spine has five vertebral bodies that extend from the lower thoracic spine (upper back) to the sacrum (bottom of the spine). The vertebral bodies of the lower back are the largest of the spine because they bear the majority of the body's weight. The paired facet joints on the back of the vertebral segments are aligned so that they allow flexion/extension but not a lot of rotation. Most causes of back pain originate in the lumbar spine. In This Article: Spine Anatomy Interactive Video Vertebral Components of the Lumbar Spine The thick oval segment of bone forming the front of the vertebral segment is the vertebral body. Each segment of the lumbar spine is comprised of the following structures: The vertebral bodies are attached to a bony arch through which all the nerve roots run.

The vertebral arch is comprised of two pedicles, the short stout processes that extend from the sides of the vertebral body and two laminae, the broad flat plates that project from the pedicles and join in a triangle to form a hollow archway (the foramen). The vertebral arches are interconnected by paired facet joints, which in combination with the disc, create a three joint complex at each vertebral motion segment. This three-joint complex at each vertebral segment (the facet joint) allows for motion in flexion, extension, rotation, and lateral bending. The facet joints have cartilage on each surface and a capsule around them. The cartilage can degenerate as one ages, and lead to degenerative arthritis. The spinous process protrudes from the junction of the two laminae and these are the ridges that can be felt through the skin along the back of the spine. Transverse processes project from the junction of the pedicles and lamina. The structures of the vertebral arch protect the spinal nerves that run through the spinal canal. A back surgery known as a lumbar laminectomy involves the removal of the laminae to gain access to the vertebral canal.

Lower Back Motion and Back Pain Fifty percent of flexion (bending forward) occurs at the hips, and fifty percent occurs at the lumbar spine (lower back). The motion is divided between the five motion segments in the lower back, although a disproportionate amount of the motion is at L4-L5 (lumbar segment 4 and 5) and L3-L4 (lumbar segment 3 and 4). Consequently, these two segments of the lower back are the most likely to break down with degeneration. As these segments break down they can become unstable with an excess of motion creating lower back pain . There are a number of non-surgical treatments available to help manage the low back pain, and a surgical fusion can help alleviate the back pain by stopping the motion. Vertebral Compression Fractures and Back Pain Since they are major load bearing structures, vertebral bodies are also prone to developing compression fractures , particularly in patients with osteoporosis (which weakens the bone). These fractures can lead to chronic back pain and progressive misalignment or deformity of the spine.

Over time, a misalignment or deformity in the spine places stress on muscles, tendons, ligaments, and bones throughout the back and can result in impaired balance or walking ability. How Many Vertebrae Does a Human Being Have? Test What You Know! Follow Us How Many Vertebrae Does a Human Being Have? Test What You Know! The human vertebral column comprises 33 vertebrae that collectively protect the spinal cord and support the entire skeletal framework of the body. The current article provides a brief description of the number of vertebrae in humans beings along with their respective location. Advertisement Gravity makes you look shorter! Gravitational force compresses your vertebral column, and it can elongate by 2-3 inches in the absence of gravity. The vertebral column (backbone or spine) is a characteristic feature of vertebrates. Extending from the base of the skull to the pelvis, it forms the axis of their skeletons. It is made up of individual units called vertebrae, within which the spinal cord is enclosed. This structure provides protection to the spinal cord, and also influences the overall posture of the animal.

Other functions include structural support for head, shoulders and chest; as well as balance and weight distribution for maintaining flexibility and mobility. The vertebral column of an adult human being is composed of 33 vertebrae, of which 24 are known as articulating or movable vertebrae, and are separated from each other by an intervertebral disc. The remaining 9 vertebrae lack the intervertebral disc and form two sets of fused structures. The total length of an adult vertebral column is about 71 cm in men and about 61 cm in women. Do you know how many vertebrae does a human being have?

Classified into five categories depending on their location in the body, the total number of vertebrae in human beings are: ♦ Cervical: 7 (C1 to C7) ♦ Thoracic: 12 (T1 to T12) ♦ Lumbar: 5 (L1 to L5) ♦ Sacral: 5 (S1 to S5, fused) ♦ Coccygeal: 4 (Co1 to Co4, fused) Total number = 33 A detailed account of the number of vertebrae in human beings as well as their names and characteristics have been provided below. Cervical (n = 7) Numbered as C1 to C7, the cervical vertebrae are present in the neck region with C1 present closest to the skull. These are smaller as compared to the other articulating vertebrae. C1 or atlas is the topmost vertebra of the spinal column, and supports the head. It freely rotates over a pivot formed by the next vertebra C2 which is termed axis or epistropheus. Together, the atlas and axis form the joint through which the skull and spine are connected.

The next four vertebrae, C3 to C6, share a similar structure, and have short and bifid spinous processes. The last vertebra in this region, C7, has long and prominent spinous process, and hence is also called vertebra prominens. Spinous process is the region for attachment of muscles and ligaments. Thoracic (n = 12) These are present in the chest region, and are designated as T1 to T12. These vertebrae have special facets for the attachment of ribs. The vertebral bodies are heart-shaped and intermediate in size as compared to the cervical and lumbar vertebrae. Being attached to the rib cage they provide lesser flexibility. Lumbar (n = 5) The five lumbar vertebrae are present in the lower back region between the rib cage and the pelvis, and are termed L1 to L5. They enable flexion and extension movements, and help to support body weight. The vertebra body is larger than the cervical and thoracic vertebrae, and is kidney-shaped. The fifth lumbar vertebra or L5, is generally the largest of all vertebrae.

Sacral (n = 5) Sacrum is a triangular, shield-shaped bony structure present below the lumbar vertebrae, and forms the posterior pelvic wall. It supports and strengthens the pelvis. The sacrum is formed by the fusion of 5 (sometimes 6) vertebrae known as the sacral vertebrae named as S1 to S5. Initially they exist as separate vertebrae, and begin to fuse after the age of 18. The fusion completes between the ages of 25 to 33. Coccygeal (n = 4) The last segment of the vertebral column is a structure called coccyx or tailbone, and represents a vestigial tail in humans. It is formed by the fusion of four small vertebrae designated as Co1 to Co4. Similar to the sacral vertebrae, these vertebrae too exist separately in the first two decades of life. The coccyx serves as an anchor for certain pelvic muscles and ligaments. The supporting structure called vertebral column is thus made up of 26 bones including 24 vertebrae and a sacrum and coccyx. Reshma Jirage

Question: How many lumber vertebrae are there in the human spine?
Answer: 5